Although DeWitt started writing poems as an undergraduate at Northeastern where he met the poets Jon Anderson, Harold Bond, Joseph DeRoche, and Don Bates and edited the university literary magazine Spectrum, he began to write seriously in graduate school at the University of Connecticut. In addition to completing his doctoral courses, he wrote his first novel, A Dance in the Market (unpublished), under the supervision of William Gaddis. At that time, he was still more interested in poetry than fiction. He won the University of Connecticut's Wallace Stevens Poetry award in 1967, presented that year by Robert Lowell. His poems began to appear in poetry magazines.
He began his teaching career at the Drexel Institute of Technology (now Drexel University) in Philadelphia in 1969. Within a year, his first book of poems Designs For/On Ahti was accepted by Blanshard Press. Then Animals, with drawings by Keith Newhouse, was published by Northeastern University in 1974. While he was teaching at Drexel, his Ph.D. was awarded by the University of Connecticut after he completed his dissertation on William Carlos Williams and women.
While he was still at Drexel, a chance teaching opportunity arose at the Philadelphia Musical Academy. He was offered the position of Chairman of General Studies at PMA, which soon became the Philadelphia College of Performing Arts. At PCPA he worked closely with colleagues Kent Christensen, William Ashbrook, and Camille Paglia, who introduced him to the world of classical music, opera, and fine art. When PCPA merged with the Philadelphia College of Art to form what would become the University of the Arts, he rejoined the faculty as a full-time professor in the Division of Liberal Arts. His experience at UArts deepened his love and understanding of jazz and of the arts in general. During this period, two chapbooks and a volume of poetry (Finger Food) appeared. His work has been selected for two poetry anthologies, the most recent being A New Geography of Poets (University of Arkansas Press, 1992).
As the 90s began, DeWitt began to turn his attention back to Stamford and his origins there. It began with a scholarly study of the popular culture of the period, concentrating especially on the development of teen culture and its love of cars. Soon he began to write poems about being a teen growing up in Stamford. Then his long-standing interest in detective novels, combined with this interest in the fifties, was sparked by a reference in a history of the fifties to the man who stole the secret of the atomic bomb at Los Alamos: Klaus Fuchs. The result was Delicious Little Traitor. And of course it had to be set in Stamford.